diff --git a/lib/loader.js b/lib/loader.js
index f4d0d98e..884e6f21 100644
--- a/lib/loader.js
+++ b/lib/loader.js
@@ -97,10 +97,14 @@ module.exports = function(content, map) {
 			map = result.map;
 			if(map.sources) {
 				map.sources = map.sources.map(function(source) {
-					var p = path.relative(query.context || this.options.context, source).replace(/\\/g, "/");
-					if(p.indexOf("../") !== 0)
-						p = "./" + p;
-					return "/" + p;
+					// trim off everything until the last occurrence of context
+					// we don't need the loader stuff in CSS source map sources.
+					var context = query.context || this.options.context;
+					var i = source.lastIndexOf(context);
+					if (i > -1) {
+						source = source.slice(i + context.length);
+					}
+					return "/" + source;
 				}, this);
 				map.sourceRoot = "webpack://";
 			}